Telephone call-bell apparatus.



N0. 684,615.' Paened Oct. l5, |901. W. S. PACA.

TELEPHDNE CALL BELL APPARATUS.

(Application filad Dec. 2S, 1900.)

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Nrrnn STATES PATEN Ferca@ VILLIAM S. PACA, OF ERIE, PENNSYLVANIA, ASSIGNOR OF ONE-HALF TO PETER H. ADAMS, OF SAME PLACE.

TELEPHONE CALL-BELL APPARATUS.

SPECIFXGATION forming part of Letters Patent N o. 684,615, dated ctober 1 5, 1901. l Application filed December 26, 1900. Serial No. 41,062; (No model.)

Be it known that LVVILLIAM S. PACA, a citizen of the United States, residing at Erie, in the county of Erie and State of Pennsylvania,

have invented certain new and useful Improvements in Telephone Call-Bell Apparatus; and I do hereby declare the following to be-a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the letters of reference marked thereon, forming part of this speciication.

My invention relates to improvements in telephone call-bell apparatus and circuits whereby two call-bells can be utilized on the same circuit without interference with each other.

In the-practice of telephone communication it is often desirable to place two stations on the same circuit, and when this is done each station has its own particular call-for example, station No. l has one ring and station No. 2 has two rings, or vice versa, the bells at both stations, however, ringing all signals sent over the line. This ringing of signals at one station when the other station is being called is annoying to subscribers and has the further objection that one station always knows when the otherstation is using the line, so that the party at one station can at any time know what the party ofthe other station is saying if he or she cares to listen thereto. This ditliculty has in some devices been overcome by the use of polarized bell-magnets at stations on the same line; but thishas been found very objectionable, as special generators and other special apparatus of delicate adjustment must be used to accomplish the desired end. To overcome these objections, I have devised a telephone and selective call-bell apparatus and so connected up this apparatus in circuit with the lines leading to the telephone-exchange that it operates only to signal the exchange and receive only the signals sent from the exchange to the station at which it is installed, neit-her the ingoing or outgoing calls from and to this station being audible 5o at the other station with a like call-bell apparatus, and vice versa, so that each station apparatus is operated Without in any manner' calling or signaling the other station located on the same circuit leading to the telephoneexchange.

The construction of the telephone and callbell apparatus and the circuits thereto is hereinafter set forth and described, and illustrated in the accompanying drawing, in which the figure is a diagrammatic illustration of telephone and call-bell apparatus and circuits therefor embodying my invention and also shows portions of. the telephone-exchange mechanism.

In the diagram the telephone exchange switchboard-jack is designated by A, and the plug by B, the circuits leading from the point and body of the plug B to the regular key C by b and b', the circuits leading from the regular key C to the party-key D by c and c', andthe circuit leading from the partykey D to the exch ange-generator E G by CZ and d', the brauch lines leading to the high-resistance coils E E bye and e', and G designates the ground connected with the resistancecoils E E. The line leading from the partykey D to the ground Gr is designated by c2. The jack-tongues are designated by ct and a and the drop connections byfand f', these parts all being parts of the exchange mechanism.

The lines forming the metallic circuit leading out from the jack A are designated as H and H', the branches leading from the line H to the telephone and call-bell apparatus at stations Nos. l and 2 as 71, and h', and the branches leading from the line H/ to the telephone and call-bell apparatus at said stations as h and h', these stations being duplicates both in construction and connections with the lines H and H.

The telephone and call-bell apparatus at station No. l comprises, substantially, a telephone-transmitter I, induction-coil I', battery 12, a receiver and switch-lever Jl, with a conductor t, leading from the induction-coil I to the receiver and through the receiver by conductor 112 and by branch line h to the main line H, and from the other side of the induction-coil I by line t to the switch-lever J, and through the switch-lever J by line j to the branch h and to the line H', and the IOO transmitter and battery 12 also connect with the switch-lever .I by a branch conductor i3, which joins conductor z", and by the line j', leading to the switch-lever J. K designates a'magneto-generator of usual construction, the crank-shaft 7c of which moves longitudinally to operate a switch L when signaling the exchange. M designates the call-bell magnets, which I make of high resistance, preferably of about two thousand ohms, though they may be of higher or lower resistance, if desired. N is a resistance-coil, preferably made of low resistance-say about five hundred ohms, but which may, if desi'red be of higher or lower resistance-and is connected with the conductor n at its junction with the conductor m, leading from the bell-magnets M to a ground G2, and with the linej, and operates not only to resist the passage of currents from the line j to ground when the bell at the other station is operated, but also operates to prevent part of the current passing through the bell beingrung from passing to the line j and then through its vline connections to the bell-magnets M at the other station. The coil N further operates to balance up the circuit when the telephone is being used, so as to eliminate induction influences, cross-talk, tre.

From the branch h a normally-closed circuit exists through line m' past the switch L and through the line m2 to the bell-magnets M, and thence through the line m to ground G2, so that a signal sent out from the exchange over the line H passes to branch h and to bell-magnets M, and thence to ground G2 at station No. l; and likewise a signal sent out on the line H passes to the` branch h and bell-magnets M and to ground G8 at station No. 2.

The sending out of the signals to station No. 1 is accomplished in the following` manner: The regular key O is moved so as to bring the conductoncontacts b2 c3 and b3 and c4 into contact, as shown in the diagram, with the party-key Din the position shown, the line cl from the generator connecting through resistance-coil E' to ground G. Now when the plug Bis inserted into the jack A a linecircuit is formed fromground G through resistance-coil E and the exchangegenerator E G to line d, to party-key D, and thence by lines c and b to the tip ot the plug B, and thence by jack-tongue c1., line ll, and branch linesv 71., m, and m2 to bell-magnet M at station No. 1, and by line m to ground G2, the return-circuit being by ground. Now if the exchange-generator is operated the bell M at station No. 1 is rung without any disturbance of the bell at station No. 2. It', however, the partykey D is moved so as to bring the line cinto contact with the lines c2 and d4 into contact with line d3, as shown in dotted lines, then the circuit is from ground G through resistance-coil E and the generator E G to line d', to party-key D, and then by line c to line b and body of plug B. Then it the plug B is inserted into the jack A the circuit will be through the jack to line H', and thence by branches 7L m m2 to bell M at station No. 2, and thence through line m to ground G3, the return-circuit being by ground. The resistance-coils E E operate to prevent the short-circuiting of the exchange-genera# tor and present suiicient resistance to prevent the grounding of the generator and permit signals to b e sent over a metallic circuit therewith. These coils also operate to balance up the generator-circuit and prevent induction through the switchboard. In each case, however, one ot the lines leading to the switch-plug B is grounded at G to prevent a false signal being transmitted to the other station in case the subscriber called removes the receiver from the switch-lever J' while the call is being made.

In calling the exchange from station No. l the generator-shaft 7a is moved laterally, so as to operate the switch L and connect the lines m and Z through the switch L, so that the circuit is through the generator K by line l through switch L to line m and through branch h to main line H and thence through the drop by connectionsfandf back through the jack-tongue a' tojack-body A and main line H back to branch h through linesj and f2 to ground at G2. The resistance-coils N at station No. 2 operate to prevent a circuit being formed with ground at station No. 2. When the exchange answers the signal, the telephonie mechanism at station No. I is op; erated in the usual manner.

At station No. 2 the signaling and telephoning apparatus and the circuits are the same in all respects, both in construction and operation, as hereinbefore described, except that the branch line h at station No. 2 connects with the main line H and branch line h with main line H. In all other respects the circuits and the operation thereof are the same as hereinbefore described.

The construction and operation ot the exchange-generator and party-key are such that when it is desired to send a call out therewith over an ordinary return-circuit line the party-key D is moved so as t0 bring the lines c d and c d' into contact, as illustrated in dotted lines, which cuts out the ground G.V Then coils E E operate to obstruct the passage of the generator-current to ground G, and when the plug B is inserted into a jack A on the switchboard the generator E G is in circuit in the usual manner and can be operated to signal4 a subscriber connected with the exchange by the usual metallic circuit.

I have thus described a convenient signaling apparatus and circuit for the construction and operation of selective call-bells upon a metallic circuit. I am aware, however, that modications thereof may be made without departing from the spirit of my invention; therefore What I claim as new, and desire to sec-ure by Letters Patent of the United States, ism*1 IOO l. In a multiple-station telephone-circuit, a telephone, a generator, and call-bell mechanism, call-bell magnets therein of relatively high resistance, a branch line normally connecting said magnets on one side with one line of the circuit leading into the exchange and on the other side with a ground, a resistancecoil between said grouudline and a branch line leading from the generator and telephone apparatus at said station to the other line of the circuit leading into the exchange, a signaling apparatus at the exchange and switch mechanism whereby signals can be sent out over either line of the main circuit leading out of the exchange, substantially as set forth.

2. In a multiple-station telephone-circuit, a call-bell and telephone mechanism at each station embodying substantially call bell magnets of relatively high resistance each normally in connection with one of the main lines leading into the exchange on one side, and with a ground on the other side, a generator normally out of circuit, which, when operated, contacts at one side with one ot the main lines leading into the exchange and back on the other mainline to a ground, substantially as and for the purpose set forth.

3. The combination of a metallic telephonecircuit extending by both of its main conductors from an exchange to two telephone-stations, a telephone and call-bell apparatus at each station, a branch line leading from one side of said metallic circuit to one side of the call-bell magnets at one station and from said magnets to a ground, a branch line leading from the other line of said metallic circuit to one side of the call-bell magnets at the other station and thence to a ground, a generator at each station, which, when operated, cuts out the bell-magnets and connects with the branch leading from the main line to the bellmagnets on one side and back through the other mainline to a ground on the other side, and telephone mechanism at each station adapted to connect with both sides of said metallic circuit, and exchange call mechanism adapted to send out calls over one side ofv said main circuit to one of said stations, and overl the other side of said main circuit to the other of said stations, substantially as and for the purpose set forth.

4. The combination in a metallic telephonecircuit extending from an exchange to two telephone-stations,a telephone apparatus connected with said metallic circuit at each station, call-bell magnets at one station connected at one side with one line ot said main circuit and at the other side with a ground, and call-bell magnets at the other station connected at one side with the other line of said main circuit and at the other side with a ground, a generator at each station adapted,

when operated, to cut out the bell-magnets' at said station and connect with the line leading from the main conductor at one side and to a ground at the other side, substantially as and for the purpose set forth.

5. The combination of a metallic telephonecircuit extending from an exchange to two telephone-stations,a telephone apparatus con-- nected with said metallic circuit at each station, a call-bell apparatus at each station comprising call-bell magnets of relatively high resistance, the call-bell magnets at one station being normally connected at one side with one line of said circuit, and at the other side with a ground, and the call-bell magnets at the other station being in like manner connected with the other main line and a ground, a generator at each station adapted, when operated, to signal the exchange over said main lines without signaling the other station, and an exchange signaling mechanism and switch mechanism adapted to ground one side of the circuit so as to send out signals over one mainline to one station and over the other main line to the other station, substantially as and for the purpose set forth.

G. The combination in a metallic telephonecircuit extending from an exchange, a telephone apparatus adapted to operate from a telephone-station over said metallic circuit, a magnetic generator and call-bell mechanism at such station comprising substantially callbell magnets of relatively high resistance normally in connection at one side with one of the lines of the main circuit and at the other with a ground, a magneto-generator normally out of circuit, which when operated, connects with branches leading to both of the lines of the main circuit, and a resistance-coil of relatively low resistance between said call-bellmagnet ground connection and a line leading from the generator to the other mainline, substantially as and for the purpose set forth.

In testimony whereof I afix my signature in presence of two witnesses.

A WILLIAM S. lPACA.

Witnesses v H. M. STU'RGEON, HENRY A. CLARK..

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